Pipecolic acid: a new type of alpha-amino acid possessing bicuculline-sensitive action in the mammalian brain.

Using unit recording and electrophoretic techniques, pharmacological properties of pipecolic acid (PA) were studied in the brain neurons of rats. PA response was blocked by bicuculline more effectively than GABA response but not blocked by strychnine. Stereochemical findings obtained using the HGS-model demonstrated that PA structure is almost the same as a part of bicuculline structure. The present results suggest that PA might be a new type of substance possessing bicuculline-sensitive action. The site of the action of PA was also discussed.